Sparking device



March 31. 1925.

H. S. COY ET AL SPARKING DEVICE Filed Oct. 18, 1920 To-aZZ whom it may) concern} Patented Mar. 31, 1925.

. 1,531,544 PATENT OFFICE.

HARRIS s. COY AND Joint n. G RRNLEE, o ANnRRsoN, INDIANA.

' SPARKING DEVICE.

Application filed October 18, 1920; Serial No. 417,698.

Be it known that we, HARRIS S. Cox and JOHN D. G-REENLEE, citizens of the United States, residing at Anderson, in the county of Madison and State of Indiana, have invented new and useful Improvements Sparking Devices, of which the following is a specification.

The invention relates to improvements in arrangements of electrodes for spark gaps of various forms and types of electrical apparatus, and more particularly to such arrangements thereof involved in spark gaps of spark plugs, or the like, used in ignition systems for internal combustion engines.

The primary object of the invention is to provide for an arrangement of electrodes for spark gaps wherein a greater eificiency, and a more steady and even spark is obtained in ignition systems for internal combustion englnes, at both the highest and lowest speeds of the latter, than has heretofore been developed in the use of known devices of like character.

Another object of the invention is to pro vide for an arrangement of electrodes for spark gaps, andone wherein, in addition to efl'ecting a maximum efliciency to and producing a more steady and even spark in an ignition system, a greater sparking length is produced than has heretofore been the case, and, consequently, better ignition can be obtained for the starting and operation of an engine at extremely low speeds, as well as for the securing of maximum efliciency at the higher or highest speeds.

With the foregoing and other objects in view, the invention resides in the. certain novel and useful arrangement and construction of parts as will be hereinafter more fully described, set forth in the appended claims, and illustrated in the accompanying and the same consists of a center core 10, of

porcelain or other form of insulating ma- I and lower surface screw-threaded for engagement with the plug opening extending through the wall of an engine. The upper inner surface of the metal shell 11 is usually provided with an annular recess 12 adapted for the reception of an annular rib 13, formed on the porcelain or insulated core 10, and threaded to receive a bushing or clamping nut 14, which, when threaded into the annular recess 12, clampsthe porcelain or insulated core 10 tightly in position-within the shell. 11; Extending vertically through the porcelain .or insulated core 10 is an electrode 15,in the form of a steel or other type of. metallicrod, which has its upper end projecting above the end of the core and threaded to receive thereon a knurled nut 16, the latteriacting as a binding post for thereception of one of the conductors of theignition circuit. The lower end ofthe electrode is generally of reduced diameter, as shown, to provide a sparking point 17. Depending from the lower edge of the shell 11 is a second electrode 18 which is suitablybent or curved so as to bring its free end into proximity to the sparking point 17 to provide a gap of desired sparking length. I

In the specific application of the invention to a spark plug as above described, and as particularly shown in Figures 2-, 3 and 4, it is contemplated to make use of one or more auxiliary or ionizing electrodes 19 and 20, the electrode 19 being usedalone and arranged in desired proximityto the center electrode sparking point 17, as shown in Figures 2 and 3, or in conjunction with the electrode 20, as in Figure 3, in which case, the latter 'is arranged at. one side of the projecting portion of the main electrode 18, both of the electrodes 19 and 20 being insulated from the main electrodes 17 and 18 In the operation of the spark plug, or

plugs, thus provided, and in the case as in Figure 2, the usual spark'gap being indicated at a, when potential is impressed at the point 17 of the electrode 15, an ionizing spark gap '6 is brought into existence between the point 17 and the auxiliary or ionizing electrode 19 slightly prior to or almost simultaneously with the establishing of the main spark, and the same effects a more rapid and intensified spark formation than is usual with ordinary types of two point spark gaps. The rapidity and intensity of this spark formation is noticeably increased, when the second auxiliary or ionizing electrode 20 is made use of, as in Figure 3 of the drawing, and in this case a second ionizing spark gap is established between it and the main electrode 18, as at 0.

In the practical use of the invention, in the use of either or both of the auxiliary or ionizing electrodes 19 and 20, it has been found that thesparking length of the main gap a can be increased to a marked degree, with a resultant longer and hotter spark, and that a maximum efficiency of the same is maintained throughout the running of an engine from minimum starting speed to the highest speed of the same. Further, by reason of effecting a more rapid formation of the spark, the minimum rate of turning of the shaft of the engine for starting purposes is less than now found necessary for its accomplishment in the present and known practice. It will be observed that in our device we make use of a central electrode 17 of usual type in connection with a ground electrode 18 also of usual type, and pro ducing the ordinary spark gap a, and that in addition we provide, as in Figures 1 and 2, a third insulated electrode 19 arranged at right angles to the electrode 18 and closer to the central electrode 17 to produce another and shorter spark gap 7), or that, as in Figures 3 and 4, we provide, in addition to the three electrodes named, a fourth insulated electrode 20 arranged at right angles to the electrode 18 to provide a third short spark gap 0 similar to the gap 1). It will further be observed that the electrodes 18 and 19 are located within the field of electromagnetic force surrounding the electrode 17 and generated in the passage of a current across the gap a. This field of force is necessarily largely concentrated in the region of the gap a, but exists to an appreciable extent through an are around the electrode 17 of 90 or more from the gap a, in the zone of which the electrode 19 lies, and we have found that in the use of the usual electrodes 17 and 18, with a sparkgap a of comparatively great length, much of this magnetic force lying outside of the line of gap 4 is dissipated and lost and that there is also considerable loss by grounding through the electrode 18, since all the magnetic force is not consumed in the production of the spark across gap 0:. Our construction makes use i of this waste magnetic force directly emitted from electrode 17, beyond the main spark zone a, to produce a spark between electrodes trodes of high capacity.

17 and 19 across gap 7), and of the waste force from electrode 18 to produce a spark sultant ionizing action produced, and we have found that by the arrangement of the auxiliary electrodes 19-2O specified an appreciable ionizing effect is obtained without the necessity of the use of auxiliary elec- To secure the effect noted, however, it is essential to dispose the electrodes 1920 with relation to the electrodes 1718 as described, as otherwise the advantages noted will be'lost and no material ionizing and auxiliary sparking actions obtained.

It is further contemplated, in the carrying out of the invention to its fullest extent, and either in lieu of the close association of the ionizing spark gaps with the main electrodes of a spark plug, or in conjunction with the same as may be desired, to make use of an ionizing spark gap at any point in the ignition circuit exteriorly of the engine and between the transformer and the It is therefore to be well understood that various arrangements, both with regard to number of auxiliary or ionizing electrodes used or their location within the ignition circuit, may be resorted to within the scope of the appended claims for the accomplishment of the desired objects and results and without departing from the spirit and scope of the same.

Having thus fully described the invention, what is claimed, is:

1. A spark plug having a central electrode, a main ground electrode having a point arranged radially to the central electrode and disposed to form a main spark gap therebetween, an insulated electrode having a spark point arranged radially to the central electrode to form a spark gap therebetweenof less length than and arranged at right angles to the first-named spark gap, and a second insulated electrode having a spark point disposed at right angles to the spark point of the ground electrode and also forming therebetween a spark gap of less length than the main spark gap.

2. In an electrical sparking device, a pair of spaced electrodes forming a main spark site terminals of an ignition circuit, and a pair of auxiliary electrodes, one arranged at one side of and in proximity to one of the main electrodes and forming an ionizing spark gap therebetween, and the other arranged at one side of and in proximity to the other main electrode and forming an ionizing spark gap therebetween, said auxiliary electrodes being insulated from said niain electrodes and from said ignition circuit.

8. In an electrical sparking device, a pair of spaced electrodes forming a main spark gap therebetween and constituting the opposite terminals of an ignition circuit, and auxiliary electrodes spaced at one side of each of said main electrodes and forming ionizing spark gaps therebetween, one of said auxiliary electrodes being disposed with respect to its compleniental main electrode atthe side thereof opposite to that of the other of said auxiliary electrodes with respect to its compleniental main electrode, said auxiliary electrodes being insulated from said main electrodes and from said ignition circuit.

4. In a spark plug, the combination with the shell and insulated core thereof, of spaced electrodes forming a main spark gap therebetween and constituting the terminals of an ignition circuit, and auxiliary electrodes spaced at one side of each of said main electrodes and forming therebetween ionizing spark gaps at right angles to the path of said main spark gap, one of said auxiliary electrodes being disposed with respect to its complemental main electrode at the side thereof opposite to that of the other of said auxiliary electrodes with respect to its complemental main electrode, said auxiliary electrodes being insulated from said main electrodes and from said ignition circuit.

5. In an electrical sparking device, a pair of spaced main electrodes, to wit, a central electrode and a ground electrode arranged at one side of said central electrode, forming a main spark gap therebetween and constituting the opposite terminals of a supply circuit, an auxiliary electrode arranged at one side of the central electrode at an angle to the ground electrode and forming with said central electrode an ionizing spark gap, and a second auxiliary electrode arranged at an angle to the ground electrode and forming therewith a second ionizing spark gap, said auxiliary electrodes being insulated from said main electrodes and from said supply circuit.

In testimony whereof We aflix our signatures.

HARRIS S. COY.

JOHN D. GREENLEE. 

